How can I determine the resulting numbers for dice throw on an animation?
Switch your Transform Orientations to Local, and once your dice has fallen and stopped, go in Edit mode and rotate it 180° or 90° or -90° on the right axis until you see the wanted face.
As Robin Betts says, if your cube has small differences of topology between its faces it may change the result, in that case you need to bake the result before rotating the cube.
Or, as suggested by user9746379, simply parent the dice to a basic cube of the same size and that contains it, this parent has the physics, not the dice, once the cube has rolled, rotate the dice as wanted, and at the end only render the dice. This way, the topology differences between faces won't be taken into account.